Cellulosic Fuel Cells Made Possible by Microorganisms

Cellulosic ethanol is, by now, known to most who ever cared about renewable and alternative energy sources. But cellulose has an energy end product other than ethanol--it could be used directly as a power source for microbial fuel cells.

Cellulosic ethanol is, by now, known to most who ever cared about renewable and alternative energy sources. But cellulose has an energy end product other than ethanol--it could be used directly as a power source for microbial fuel cells. Basically, a microbial fuel cell needs two types of microorganisms to work: one to digest the cellulose and another to produce the energy. The bacteria that digest cellulose produce simple molecules used by the other type of bacteria to create energy. The other type is called exoelectrogenic bacteria. The name came to be because usually, microorganisms generate electrons from food sources but retains them inside. Exoelectrogenic bacteria, however, can transport the electrons outside the cell for use.

One study from the Pennsylvania State University found that because of diversity in microbial species in wastewater systems, the dirty water could be used for cellulose degradation and energy production. Extra cellulose-degraders would be needed to speed up the process though. Another study from the Ohio State University through discovered both cellulose-digesting bacteria and exoelectrogenic bacteria from cow's guts that could be used to process grass or even manure. The team from Ohio State was already able to harness power from their own microbial fuel cells to charge AA batteries, but so far, there are no indications that we'll be using microbial fuel cells anytime soon.